A series of tests were conductedin a guardedhotbox to evaluate the thermal performance (R-value) of wall constructions typical of light-frame buildings that are commonly used in agricultural applications. The systems were insulated with either a commercially available foil-faced bubble pack material (FFBP) or foil-faced polyisocyanurate (PIR) foam board. Tests were conducted under two different temperature conditions, chosen to be representative of a midwestem winter and summer.

Temperatures of the surfaces bounding the reflective airspaces were measured and the R-values were calculated using the equations developed by Yarbrough (1983). These data were used in the ASHRAE series/ parallel calculations and the resultant R-value was compared to the measured R-value. Agreement was usually better than 10%